1. Field
Embodiments described herein generally relate to collector compositions and methods for using same to recover one or more purified materials. More particularly, such embodiments relate to collector compositions that include one or more etheramines and one or more amidoamines and an inverted froth flotation process for using the collector compositions to enrich an iron mineral from a silicate-containing iron ore.
2. Description of the Related Art
Froth flotation is a physiochemical mineral concentration method that uses the natural and/or created differences in the hydrophobicity of the minerals to be separated. To enhance an existing or to create new water repellencies on the surface of the minerals, certain heteropolar or nonpolar chemicals called collectors are added to an aqueous slurry containing the mineral(s) to be separated or purified. These chemicals are designed to selectively attach to one or more of the minerals to be separated, forming a hydrophobic monolayer on their surfaces. The formation of the hydrophobic monolayer makes the minerals more likely to attach to air bubbles upon collision. The mass of the combined air bubble/mineral particles is less dense than the displaced mass of the pulp, which causes the air bubble/mineral particles to float to the surface where they form a mineral-rich froth that can be skimmed off from the flotation unit, while the other minerals remain submerged in the pulp. The flotation of minerals with a negative surface charge, such as silica, silicates, feldspar, mica, clays, chrysocola, potash and others, from a pulp can be achieved using cationic collectors. In iron and phosphate beneficiation processes the impurities are typically floated away, leaving the valuable component behind. This process is called “reverse flotation.” Cationic collectors are organic molecules that have a positive charge when in an aqueous environment. Typically cationic collectors will have a nitrogen group with unpaired electrons present.
In reverse flotation, impurities are floated out of the mineral of value. In particular, iron ore, calcium carbonate, phosphate, and feldspar are frequently beneficiated in this manner. In many cases minerals containing silicate are the main components of these impurities which cause quality reductions in the end product. The minerals containing silicate include quartz, mica, feldspar, muscovite, and biotite. A high silicate content lowers the quality of iron ore concentrate, which in Brazil, for example, is purified via flotation using alkyl ether amines and alkyl ether diamines so that high-grade steels can be produced from the low-silicate concentrate. The collectors for silicate flotation which are described in the prior art, however, exhibit inadequate results with respect to selectivity and yield.
There is a need, therefore, for improved collector compositions and uses thereof in ore beneficiation processes.